Patients who are critically ill can develop acute insulin resistance manifesting as hyperglycemia and hyperinsulinemia. Rarely, patients can develop extreme insulin resistance, defined as having an insulin requirement of >3 units/kg/day (1). We report here a case of a septic patient who developed acute extreme insulin resistance in the critical care setting that was difficult to treat, and after 4 days, reversed rapidly, necessitating rapid down-titration of the intravenous insulin infusion and close blood glucose monitoring to avoid hypoglycemia. This case illustrates a general lack of understanding of 1) why severe insulin resistance occurs, 2) how to treat this clinical dilemma safely and effectively, and 3) what the treatment goals should be to achieve the best medical outcomes.
A 64-year-old Hispanic woman with type 2 diabetes, hypertension, hyperlipidemia, and hypothyroidism was initially admitted with a right humeral head and neck fracture, right malleolar fracture, and navicular fracture. One day after admission, she developed acute hypoxemic respiratory failure requiring continuous positive airway pressure and transfer to the medical intensive care unit (MICU). Before hospitalization, her diabetes regimen included sitagliptin 50 mg daily, metformin 1,000 mg daily, and human insulin 70/30 combination (70% human insulin isophane suspension and 30% human insulin) at a dose of 40–50 units twice daily. Her A1C was 8.5%, and her weight on admission was 110 kg, with a BMI of 44.4 kg/m2. Physical exam was notable for central obesity. She denied any complications of diabetes.
The primary team had started the patient on 40 units of subcutaneous insulin glargine daily and a high-dose supplemental corrective scale with insulin lispro to be given every 6 hours. Shortly after transfer to the MICU, the patient developed severe hyperglycemia. When …